The goal of this proposed investigation is to identify Spanish grammatical structures that are reliable identifiers of language impairments and less vulnerable to variation in bilingual populations. Spanish- speaking children with specific language impairments (SLI; unexplained limitations in language ability, particularly with morphosyntax) show difficulties with the production of grammatical elements, such as articles, object pronouns, plural marking, adjective agreement, verb marking, auxiliary verbs, and the subjunctive mood, when compared to typically developing (TD) children. Emerging evidence suggests that some of these grammatical structures are not only difficult for children with language impairments, but are also vulnerable to changes in language proficiency in bilinguals. The possibility of an interaction between language impairments and degrees of bilingual proficiency pose a significant problem for language assessment practices in bilinguals: lower accuracy rates in grammatical tasks could be a result of either typical acquisition in bilingual children or language impairments. The purpose of this study is to investigate the potential confounding effect between levels of bilingual proficiency and language impairments in Spanish-speaking children by: (a) Examining the production of grammatical structures that have already been found to be problematic for Spanish-speaking children with language impairments in children with and without SLI from three language proficiency groups: monolingual Spanish (MS), Spanish-dominant with intermediate English proficiency (SD) and balanced Spanish- English bilingual (BB); and (b) Identifying a set of grammatical structures that are less vulnerable to bilingual variation, and, therefore, reliable identifiers of language impairments in Spanish-English bilingual children. TD children and children with SLI will be matched by age (+ or - 3 months), gender, mother's education level, and language proficiency group. The experimental measure consists of a comprehensive elicitation task including articles, object pronouns, plural marking, adjective agreement, verb marking, auxiliary verbs, and the subjunctive mood. This study will improve the accuracy of language assessment practices for Spanish-English bilingual children in the United States by further describing baselines of typical bilingual development and by providing methods to improve identification of language impairments.